If you are shown the above error message, there are a number of things you can try:
Make sure that the watch is fully snapped into the dock.
Make sure that no pins are bent in the dock.
Connect the watch directly to the computer. Do not use a hub.
Try another USB port, or check that other USB devices work in the port.
If possible, try a different computer to determine where the problem is.
If these steps don't help then try a factory reset.